Green thumbs up: Planting projects for the fall season

Suzanne Mahler

Thursday

Sep 30, 2010 at 12:01 AMSep 30, 2010 at 12:52 PM

To prevent a total meltdown prior to lethal frosts, I take a stroll through my landscape as the month of September draws to a close. I begin compiling a lengthy list of all that could potentially be done given an ideal world with unlimited time.

Despite several days of summer-like weather during the past week, chilly temperatures are inevitable in the weeks to come as the fall season officially gets underway.

To prevent a total meltdown prior to lethal frosts, I take a stroll through my landscape as the month of September draws to a close, critically analyzing my lawn, gardens and shrubbery. I begin compiling a lengthy list of all that could potentially be done given an ideal world with unlimited time. During the evening hours, the list is prioritized with the knowledge that only a fraction of the chores are likely to be tackled before the snow flies.

The fall season is my preferred time of year to expand and rejuvenate existing borders or prepare new gardens. With soils warm, dry and workable, turning the soil is readily accomplished. After removing the surface layer of turf or weeds, layers of compost, shredded leaves, well-decomposed manure, I mix peat moss and lime into the underlying soil with a digging fork. The presence of plentiful organic matter improves drainage and airflow in clay soils. The addition of humus to dry sandy soils enhances water and nutrient retention.

Some of these new spaces will be used to accommodate the lingering collection of orphans that remain assembled in my driveway and beneath my weeping cherry tree. In addition, many perennials, trees and shrubs have been marked down at our local nurseries and are just waiting to be adopted.

Although some of these plants may not look their best, many just require a little trimming and nurturing to regain their tidy appearance. Plants grown at quality nurseries are usually watered regularly and are merely suffering from the effects of pot culture, or they may be entering their dormant period.

Ideally, all plants perform best when a hole 2 to 3 times wider than their root ball is prepared, ensuring adequate room for new growth and root development. Avoid the temptation to squeeze new acquisitions into tight spaces between established plants.

Before transferring container-grown plants into the ground, be sure to inspect the root systems as you remove them from their pots. Several months in confined quarters often result in pot-bound specimens. Roots should be gently eased apart, if possible, but more ruthless action may be required when the roots are tightly tangled. A hand claw or screwdriver may prove effective to loosen the root ball and occasionally a sharp knife may be required to cut through dense, fibrous masses (make 3 or 4 vertical slices, which will stimulate new root growth).

If pot-bound plants are inserted without some manipulation, roots may continue to grow inward, limiting uptake of moisture and nutrients, which often result in their demise. When these failed plants are lifted, their root balls have usually retained the form of their original containers with no evidence of new root development.

Planting depth is also a critical factor for survival, especially for woody trees and shrubs. The depth of a planting hole should be just deep enough to enable you to reset the tree or shrub at the same level as it was previously growing in its container, with the roots just beneath the soil surface and the woody stems or the flare at the base of the tree exposed. Since this is where the plant breathes, if this area is covered with too much soil or mulch, the plant slowly suffocates and may eventually die.

Similarly, many perennials like iris, daylilies and peonies will not bloom if planted too deeply, while others may rot if the crown (where the roots meet the stems) is too far below the soil surface. Poor winter drainage is also a major contributor to plant failures.

A new fall garden is an ideal site to insert a diversity of spring-flowering bulbs. No landscape seems complete without a few patches of early-blooming snowdrops, crocuses, daffodils or tulips, and autumn is the season for planting these harbingers of spring. Purchase top-sized bulbs from local nurseries or reliable catalog sources.

Bulbs sold individually tend to be larger and more expensive, but they are worth the investment as they usually bloom more reliably with flowers of greater size. This is especially true of daffodil bulbs, as those having multiple noses produce more flowers.

All bulbs prefer loose, porous, fertile soils with excellent drainage to prevent rotting during dormancy. Raised beds may be necessary in low, damp locales. Be sure to read labels for recommended planting depths and keep a ruler handy while planting to ensure reasonable accuracy. The majority of spring-flowering bulbs are best planted in clumps or drifts.

I prefer to use a shovel to dig one large hole for each grouping, loosening the soil in the bottom of the hole and spacing the bulbs within that hole. Since the foliage of daffodils tends to linger well into the summer, consider planting them in the middle of a mixed border where their fragrant blooms will delight in spring and the expanding leaves of perennials will help to conceal the declining leaves once their blossoms fade.

While bulbs contain all the nutrients they require to flower the first year, bulbs need phosphorus to flower in subsequent seasons. Mix super phosphate or bulb booster in the bottom of the planting hole because this mineral moves very slowly through the soil. Although bone meal serves as a source of this nutrient, you may wish to avoid its use because animals often detect its scent and dig up newly planted bulbs.

Be sure to firm the soil around your new plantings and water deeply, dispensing supplemental moisture until the ground freezes if Mother Nature does not provide.

Suzanne Mahler is an avid gardener, photographer and lecturer. Her weekly gardening column ‘Green Thumbs Up’ has appeared in Community Newspapers for more than a decade. She is an overseer for the Massachusetts Horticultural Society and is employed at two garden centers.

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